OEM Software

Does anyone know any good places to get legitimate OEM software to bundle with a new PC? I'm probably going to be making one for someone who wouldn't want a pirate OS etc, and the cheapest i can find for XP home is £90. I can't imagine the small companies who make computers paying this out as it's quite a lot for a £400 PC. Does anyone know any reliable cheap places to buy OEM software?

xp home is £72 on scan:

http://www.scan.co.uk

Ask them if they would consider using linux, redhat 8 is pretty dam good.